Drug & supplement interaction

L-citrulline + Naloxegol

Naloxegol brand name: Movantik.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between L-citrulline and Naloxegol in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Naloxegol states a food rule worth keeping to.

Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

L-citrulline and Naloxegol

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Naloxegol and L-citrulline in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

L-citrulline safety at a glance

L-citrulline overall Use caution Generally well tolerated in healthy adults, but long-term safety is not fully studied.
Pregnancy Avoid There is not enough safety data, so it is best to avoid supplements during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid supplemental use.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Naloxegol and L-citrulline? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Naloxegol

Interactions in our licensed database are recorded against drug classes, not just single drug names. Naloxegol is filed under 2 classifications — cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. L-citrulline has documented interactions with 2 drug classes — the most serious being antihypertensive drugs (moderate) and phosphodiesterase-5 inhibitors (moderate) — and none of Naloxegol’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

L-citrulline Does Interact With Other Medications

L-citrulline has 178 moderate known drug interactions in our database — Naloxegol isn’t one of them. If you take anything else, check it against the full list below.

Moderate 178 No known interaction 2,652 (incl. Naloxegol)
Taking anything else?

Check Another of Your Medications Against L-citrulline

Covers the 2,830 medications we’ve checked against L-citrulline. Pick one to open its full report.

What to actually watch for

What L-citrulline Itself Has Been Linked To

This is not an interaction — nothing below involves Naloxegol. It is the side-effect record for L-citrulline on its own, from the licensed Natural Medicines monograph. If something new turns up after you add L-citrulline, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Raised blood pressure Worth acting on Additional detail

    “Orally, 2 of 25 patients with pulmonary hypertension reported cough while taking 1 gram of powdered L-citrulline in water daily.”

    L-citrulline · Natural Medicines adverse-effect record, reported in cough.

    1 source cited
    1. 94963. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed

    “Orally, 2 of 25 patients with pulmonary hypertension reported increased urinary frequency and edema while taking 1 gram of powdered L-citrulline in water daily.”

    L-citrulline · Natural Medicines adverse-effect record, reported in hypertension.

    1 source cited
    1. 94963. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed
  • Heartburn / Stomach upset Additional detail

    “Orally, gastrointestinal intolerance, stomach discomfort, and heartburn have been reported with L-citrulline use.”

    L-citrulline · Natural Medicines adverse-effect record, reported in dyspepsia.

    3 sources cited
    1. 94955. Balderas-Munoz K, Castillo-Martínez L, Orea-Tejeda A, et al. Improvement of ventricular function in systolic heart failure patients with oral L-citrulline supplementation. Cardiol J 2012;19:612-7. PubMed
    2. 94963. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed
    3. 94966. Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res 2010;24:1215-22. PubMed
  • Cough Additional detail

    Recorded for L-citrulline in the same Natural Medicines adverse-effect record shown under Raised blood pressure above.

  • Swelling Additional detail

    Recorded for L-citrulline in the same Natural Medicines adverse-effect record shown under Raised blood pressure above.

Everything above comes from the Natural Medicines adverse-effect record for L-citrulline — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Naloxegol’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Naloxegol column appears here.

How to take them

Some Naloxegol Products Have a Food Rule — L-citrulline Should Not Break It

At least one FDA label for a product containing Naloxegol says to take it on an empty stomach. Most supplements — L-citrulline included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Naloxegol on its own and move L-citrulline to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Naloxegol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

(2.1) Take on an empty stomach at least 1 hour prior to the first meal of the day or 2 hours after the meal.

From the Dosage and Administration section of the FDA label we read for Naloxegol — where that label names a specific product, the instruction is that product's. See the Naloxegol drug page ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About L-citrulline or Naloxegol

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers L-citrulline or Naloxegol, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Naloxegol

This page covers L-citrulline only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Naloxegol page lists 138 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 94 moderate · 41 minor.

From our pharmacist’s overview on the Naloxegol page

“Naloxegol (Movantik) relieves the constipation that opioids cause, and this is a list that deserves real care before you add anything from it. Nearly all of the trouble traces to a single enzyme, CYP3A4, which the body relies on to clear naloxegol.”

Reviewed by 2 · Jul 18, 2026

Open the Naloxegol interaction page

One more smart check

Taking L-citrulline as Part of a Dietary Supplement Product? Check It for Interactions

We hold 63 real supplement products containing L-citrulline, each one broken down to its full ingredient list — and combination products often carry several ingredients besides L-citrulline. Even though L-citrulline itself has no known interaction with Naloxegol, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where L-citrulline and Naloxegol Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement L-citrulline
Steady interest

#793 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Naloxegol
Steady interest

#1,564 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every L-citrulline reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The L-citrulline and Naloxegol records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About L-citrulline

What is L-citrulline?

L-citrulline
  • Exercise performance
  • Muscle soreness and fatigue
  • Blood flow and circulation
  • Erectile dysfunction
  • Blood pressure support

L-citrulline is an amino acid that the body turns into L-arginine to help make nitric oxide, which relaxes blood vessels and may improve blood flow. It is popular for exercise performance and circulation, but the evidence is mixed and most benefits are modest. It appears generally well tolerated, but talk to your pharmacist or doctor before starting, especially if you have a health condition or are pregnant.

Amino acid (made by the body and found in foods; supplements are usually made by fermentation) · Powder, capsules, tablets; also sold as citrulline malate

An interaction check asks whether these two react with each other — it does not ask whether L-citrulline is a good idea for someone in your situation. Here is what our L-citrulline record says about it on its own.

L-citrulline: dosing

There is no official standardized dose of L-citrulline, and the right amount can depend on the form (plain L-citrulline versus citrulline malate) and the reason for use. Doses used in studies vary widely.Because of this, the best approach is to follow the directions on the product label and start with the lowest suggested amount.

From our L-citrulline monograph — the full record covers uses, side effects and every documented interaction.

Read the full L-citrulline monograph & all interactions
Medication

About Naloxegol

What Is Naloxegol Used For?

Brand name: Movantik

Movantik (naloxegol) is used to treat opioid-induced constipation (OIC) — constipation caused by opioid pain medications — in adults who have chronic non-cancer pain. It is also approved for adults with chronic pain related to prior cancer or its treatment, as long as they don't need frequent (roughly weekly) increases in their opioid dose.

It is not indicated for constipation from other causes, and it is not approved for use in children.

Most-Reported Side Effects for Naloxegol

From FAERS, the FDA’s public side-effect reporting system (3,902 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 380 reports
Constipation 375 reports
Nausea 329 reports
Abdominal pain 258 reports
Abdominal pain upper 228 reports
See full Naloxegol drug information
Keep checking

Other Drugs & L-citrulline

Browse every other medication we’ve checked against L-citrulline — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
178Moderate
0Minor
2,651No known interaction
178 Moderate 2,651 No interaction
Moderate

178 interactions

Showing 60 of 178 moderate interactions — see all 178 on the L-citrulline page.

No interaction 2,651 drugs checked — show the list

We also checked L-citrulline against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,651 medications checked with no known interaction — see the full L-citrulline list.

See the full L-citrulline interactions page
See every supplement checked against Naloxegol, ranked by severity
Evidence & sources

L-citrulline References

The 8 references that drive our L-citrulline monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Cheng JW, Balwin SN. L-arginine in the management of cardiovascular diseases. Ann Pharmacother 2001;35:755-64. PubMed
  2. Schwedhelm E, Maas R, Freese R, et al. Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolism. Br J Clin Pharmacol 2008;65:51-9. PubMed
  3. Romero MJ, Platt DH, Caldwell RB, Caldwell RW. Therapeutic use of citrulline in cardiovascular disease. Cardiovasc Drug Rev 2006;24:275-90. PubMed
  4. Balderas-Munoz K, Castillo-Martínez L, Orea-Tejeda A, et al. Improvement of ventricular function in systolic heart failure patients with oral L-citrulline supplementation. Cardiol J 2012;19:612-7. PubMed
  5. Sharif Kashani B, Tahmaseb Pour P, Malekmohammad M, et al. Oral l-citrulline malate in patients with idiopathic pulmonary arterial hypertension and Eisenmenger Syndrome: a clinical trial. J Cardiol 2014;64:231-5. PubMed
  6. Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res 2010;24:1215-22. PubMed
  7. Mirenayat MS, Moradi S, Mohammadi H, Rouhani MH. Effect of L-citrulline supplementation on blood pressure: a systematic review and meta-analysis of clinical trials. Curr Hypertens Rep. 2018;20(11):98. PubMed
  8. Xu Z, Liu C, Liu S, Zhou Z. Comparison of efficacy and safety of daily oral L-arginine and PDE5Is alone or combination in treating erectile dysfunction: A systematic review and meta-analysis of randomised controlled trials. Andrologia. 2021:e14007. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking L-citrulline and Naloxegol Together: Common Questions

Is it safe to take L-citrulline with Naloxegol?
We do not list a known interaction between L-citrulline and Naloxegol. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take L-citrulline and Naloxegol at the same time of day?
At least one FDA label for a product containing Naloxegol says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Naloxegol on its own and move L-citrulline to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the L-citrulline and Naloxegol combination checked?
Interactions in our licensed database are recorded against drug classes. Naloxegol is filed under 2 classifications, and L-citrulline has documented interactions with 2 drug classes — none of Naloxegol's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does L-citrulline interact with any other medications?
Yes. L-citrulline has 178 documented drug interactions in our database — Naloxegol is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Naloxegol interact with any supplements?
Yes. Naloxegol has documented interactions with 138 supplements in our database — L-citrulline is not one of them. The Naloxegol interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

L-citrulline monograph Uses, safety profile, and every drug interaction in one place Naloxegol drug information The full plain-English guide to this medication Naloxegol supplement interactions Every supplement checked against Naloxegol, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Naloxegol and L-citrulline?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.